Power-operated telescoping seating structures



3,069,732 POWER-OPERATED TELESCOPING SEATING STRUCTURES Filed April 21, 1958 R. J. MURPHY Dec. 25, 1962 6 Sheets-Sheet l INVENT OR.

RAYMOND J. MURPHY ATT Y,

Dec. 25, 1962 R..J. MURPHY 3,069,732

POWER-OPERATED TELESCOPING SEATING STRUCTURES Filed April 21, 1958 s Sheets-Sheet 2 I'III'IIIA WEE! i l i 5' n\\\\\\\ if .1 l I FIG.2

INVENTOR.

ATT'Y.

c 3! 0 2 on 3 33 w 4 3 1 7 3 T 6 7 C. 2 8 0 9 3 3 2 POWER-OPERATED TELESCOPING SEATING STRUCTURES 6 Sheets-Sheet 5 R. J. MURPHY Dec. 25, 1962 Filed April 21, 1958 RAYMOND J. MURPHY FIG. 3

Dec. 25, 1962 R. J. MURPHY 3,

POWER-OPERATED TELESCOPING SEATING STRUCTURES Filed April 21, 1958 s Sheets-Sheet 4 FIG. 5

FIG. 6

INVENTOR. RAYMOND J. MURPHY ATTY.

Dec. 25, 1962 RPH 3,069,732

POWER-OPERATED TELESCOPING SEATING STRUCTURES Filed April 21, 1958 6 Sheets-Sheet 5 ATT Y.

Dec. 25, 1962 R. J. MURPHY 3,069,732 POWER-OPERATED TELESCOPING SEATING STRUCTURES Filed April 21, 1958 6 Sheets-Sheet 6 rat This invention relates in general to certain new and useful improvements in gymnasium equipment and, more particularly, to a power-operated telescoping seating structure.

It has become a common practice in school auditoriums, gymnasiums, and the like, to install so-called telescoping bleachers. These bleachers ordinarily consist of a plurality of interconnected steel frames which are slidably joined so that the several sections of the bleacher can be pushed telescopically together to form a compact assembly against one wall of the gymnasium when not in use. Seating structures of this type ordinarily range in length from twelve to eighteen feet and may consist of six to twenty-four tiers depending upon the size of the auditorium in which the seating structure is installed, and, moreover, a gymnasium installation frequently utilizes several sets of bleachers arranged in contiguous relationship along one or more walls of the building.

Since bleachers of this type must be capable of supporting the total weight of the large number of persons seated thereon, the framework must be quite heavy with the result that it ordinarily requires the efforts of several men to shift the structure to and from open and closed positions. Furthermore, when several men pull the structure to the open position, it frequently happens that the workmen do not pull with equal force with the result that the strucure is not exended in :a perpendicular direction from the wall on which it is attached. Therefore, when the adjacent seating structures are pulled outwardly from the wall, there will be some marginal interference between the two seating structures which will necessitate the workmen realigning the structures.

It is therefore, the primary object of the present invention to provide a power-operated telescoping seating structure which is capable of being quickly and easily shifted into open and closed position.

It is also an object of the present invention to provide a power-operated telescoping seating structure of the type stated which permits telescoping movement of the seating structure in a relatively straight line and thereby eliminate marginal interference between adjacent seating structures.

It is a further object of the present invention to provide a telescoping seating structure of the type stated wherein the power-driven assembly is embodied in the seating structure and, therefore, eliminates the necessity for auxiliary moving devices.

With the above and other objects in view, my invention resides in the novel features of form, construction, arrangement, and combination of parts presently described and pointed out in the claims.

In the accompanying drawings:

FIG. 1 is a fragmentary front elevational view, partlybroken away, of a power-operated telescoping seating structure constructed in accordance with and embodying the present invention;

FIG. 2 is a fragmentary sectional view thereof taken along line 2-2 of FIG. 1,,and showing the seating structure in the retracted or closed position;

FIG. 3 is a diagrammatic view showing the seating structure in the extended or opened position;

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 1;

3,659,732 Patented Dec. 25, 1962 FIG. 5 is a fragmentary side elevational view of the portion of the seating structure shown in FIG. 4;

FIG. 6 is a fragmentary sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a fragmentary sectional View taken along line '77 of FIG. 2;

FIG. 8 is a fragmentary rear elevational view and showing the cable and drum assembly forming part of the present invention; and

FIG. 9 is a fragmentary sectional view taken along line 99 of FIG. 8.

Referring now in more detail and by reference characters to the drawings which illustrate a practical embodiment of the present invention, A designates aitelescoping seating structure or bleacher which includes a rear frame 1 consisting of a plurality of transversely spaced uprights 2, each in turn being provided at its upper end with a plate 3. Adjacent their lower ends, the uprights 2 are also cross connected by a formed channel plate 4 which is welded, riveted, or otherwise rigidly attached thereto, and the uprights 2 are also cross connected by an angle member 5.

Mounted on the upper end of an extending horizontal between the uprights 2 is a seat board 6 and similarly mounted directly beneath and extending along the seat board 6 is a fascia board 7. At their lower ends each of the uprights 2 is rigidly welded to a plurality of horizontal foot-forming frames 8, 8 which are adapted to rest directly upon the gymnasium floor so that when each of the uprights 2 is rigidly attached to the gymnasium wall or similar structure B by means of conventional tie bolts 9, the entire top or main seating tier will be rigid, permanent and stationary. Welded to the laterally presented outer face of each foot-forming frame 8, 8' is an outwardly and downwardly presented longitudinal slide flange 10 for purposes presently more fully appearing.

Rigidly secured to each of the uprights in outwardly spaced relation to the seat board 5 is a forwardly extending horizontal beam 11 for slidable track-forming engagement with a slide fitting 12 which is in turn welded to the upper ends of an auxiliary uprights 13, the latter being similar to the uprights 2 previously described. Welded to and extending upwardly from the forward end of the beam 11 is a seat mounting plate 14 for supporting a seat board 15' and fascia board 16, the latter being substantially similar to the previously described seat board 6 and fascia board 7. Also bolted or otherwise rigidly secured to the upper side of the beam 11 and located between the seat boards 6, 15 is a foot board 1'7. When the seating structure is in operative use, a spectator may be seated upon the seat board 6 and rest his feet upon the foot board 17 directly below and in front of the fascia board '7.

Each of the uprights 13 corresponds to one of the uprights 2 except that the uprights 13 are not rigidly attached to either the wall or floor and there are a plurality of uprights 13, each being cross connected by an angle member 5' in the same manner as the uprights are cross connected by angle member 5. At their lower ends the uprights 13 are welded to first extensible under-frame carriages 18, 18, thereby forming a first sliding telescoping tier T which can be shifted inwardly toward the wall B in relation to the main seating tier. Thus, the telescopic substructure of seatingstructure A consists of a plurality of substantially identical tiers T, each consisting of a plurality of laterally aligned uprights 13 formed by having a seat board 15, a fascia board 16, and a foot board 17 supported by under-frame carriages and laterally connected by angle members 5. Each of the tiers T may include any number of laterally spaced uprights 13 depending upon the length of the seating structure and any number of tiers T may be employed depending upon the number of seats desired and the height to which the structure is to be carried. In actual installations, it has been found that it is possible to fabricate seating structures of this type with at least as many as twentyone tiers rising to an overall height at the wall of approximately nineteen feet.

The first extensible under-frame carriages 18, 18"are each resiliently connected to rollers 19 in the manner described in the application of George R. Chervenka, Ser. No. 346,870, filed April 6, 1953, now US. Patent No. 2,870,492, issued January 27, 1959, and the rollers 19 rest on the gymnasium floor. wardly presented lateral faces of the carriages 18, 18 adjacent the forward ends thereof, are upturned ears 20 and similarly welded to the opposite lateral faces of the carriages 18, 18 are slide flanges 21. The under-frame carriages 18, 18' are also each provided with a short locking plate 22 which extends outwardly above the ear 21 as best seen in FIG. 6. The next seven succeeding extensible tiers T comprising a second group of tiers are similarly provided with under-frame carriages 23, 24, 25, 26, 27, 28, 29, 23', 24, 25, 26, 27, 28, 29', which also include rollers 19, ears 20, slide flanges 21, and locking plates 22. As a result of this structure, the ears 20 on the carriages 18, 18' slidably engage the flanges on the foot-forming frames 8, 8' and the ears on the carriages 23, 23 slidably engage slide flanges 21 on the carriages 18, 18. At the same time, the locking plates 22 prevent vertical shifting movement of the carriages 18, 18, 23, 23'. Similarly, in the carriages 24, 25, 26, 27, 28, 29, 24, 25, 26', 27, 28, 29, the ears 20 slidably engage the slide flanges 21 of the carriage adjacent thereto as best illustrated in FIG. 6. The ninth extensible under-frame carriages 30, 30' are also provided with rollers 19 and on their inwardly presented faces with ears 20 for engagement With the slide flanges 21 of the carriages 29, 29'. Thus, when the seating structure A is in closed position, the foot-forming frames 8, 8' and carriages 18, 23, 24, 25, 26, 27, 28, 29, 30, 18', 23, 24, 25', 26', 27', 28, 29', 30' will be in lateral alignment.

Welded to one lateral face of each of the carriages 30, 30' and extending forwardly therefrom are connecting plates 31, 31' which are, in turn, welded to underframe carrliages 32, 32', the latter also having rollers 19 and slide flanges 21 for engagement withthe cars 20 on the adjacent carriages 33, 33. Thus, by means of this construction, the two groups of tiers are interconnected by means of the connecting plates 31, 31'. The next succeeding carriages 34, 35, 36, 37, 38, 39, 48, 41, 34', 35', 36, 37', 38, 39', 40', 41' are similar in construction to the carriages 34, 34' and include ears 20 for slidable engagement with the flanges 21 of the adjacent carriage. .When the seating structure is closed, the carriages 33, 34,35, 36, 37, 38, 39, 40, 41, 33', 34, 35, 36, 37, 38', 39, 40', 41 will be in lateral alignment. 'Whenthe telescopic bleacher structure A is unloaded, each of the uprights 2, 13 and is related structure will be resiliently held upwardly with respect to the floor 1 so that the entire seating structure A will roll freely inwardly and outwardly on the rollers 19. However, when appreciable Weight, Such as the Weight of a number of spectators, is brought to bear on the structure A, it will shift downwardly with respect to the roller 19 and come to rest 'irnmovably in a stationary position on floor f so that the load will be carried through the uprights 2, 13 into the carriages which, in turn, rest snugly and directly upon the floor f. 'Each of the carriages are provided at their forward ends with stop forming flanges 42 which extend transversely of the ears 21 and similarly the carriages are provided at their rear margins with transver sely extending stop forming flanges 43 so that when thecarriages are movedto and from open and closed position, the ears 20 will abut the stop forming flanges Welded to the in- 42, 43 and thereby prevent the several carriages from becoming disengaged from each other.

Bolted to the upwardly present surface of the footforming frame 8' at the rear ends thereof is an upstanding bracket 44 for supporting a pair of pulleys 45, 46. Bolted or otherwise rigidly secured to the upwardly presented face of the foot-forming frames 8, 8' and at the forward ends thereof are brackets 47, 47 which extend forwardly of the foot-forming frames 8, 8' and rotatably mount vertical pulleys 48, 48. Rigidly bolted to the upper face of the carriages 18, 18 at the rear ends thereof are brackets 49, 49' provided with a'rearwardly and upwardly inclined and bent arms 50, 50', the outer ends of which rotatably support inclined pulleys 51, 51. Mounted on the upwardly presented face of the forward ends of the carriages 18, 18 are brackets 52, '52 which extend upwardly and forwardly of the forward margins of the carriages 18, 18' and have Vertical pulleys 53, 53' rotatably mounted thereon. Each of the under-frame carriages 23, 24, 25, 26, 27, 28, 29, 23', '24,'25', 26, 27', 28, 29 are also provided with brackets 49, 49 having angularly bent arms 50, 50 for journaling inclined pulleys 51, 51 and the brackets 52, 52' for rotatably supporting vertical pulleys 53, 53'. The carriages 30, 38 are provided On their rear ends with brackets 49,49 having angularly bent arms'50, 50 for journaling inclined pulleys 51, 51', but the pulleys at the forward ends of the carriages 30, 30 are omitted. The underframe carriages 32, 32' omit the brackets 49, 49' and inclined pulleys 51, 51, but are provided on the upper surfaces of their forward ends with upwardly and forwardly extending brackets 54, 54 for journaling and vertical pulleys 55, 55. The under-frame carriages 33, 34, 35, 36, 37, 38, 39, 40, 33, 34, 35, 36', 37', 38', 39, 40' are also provided on their forward ends with brackets 54, 54 for journaling pulleys 55, 55' and on their rear ends with brackets 56, 56' having angularly bent upwardly inclined arms 57, 57' for rotatably supporting inclined pulleys 58, 58. The arms 57, 57' are similar in' construction to the arms 58, 58 previously described, but are bent or twisted in the opposite direction so that the pulleys 58, 58 will be inclined oppositely to the pulleys 51, 51'.

Bolted to the gymnasium floor adjacent the wall B and intermediate the uprights 2 is an upstanding rectlinear frame 59, the upper end of which is provided with a motor mount 68 for supporting an electric motor 61. Extending outwardly from the motor 61 is a drive shaft 62 provided with a worm 63 which meshes with a vertical pinion 64, the latter being rotatably supported in aligned bearings 65, 66, 67 mounted in the frame 59. Integral and coaxial with the pinion 64 is an enlarged pinion 68 which meshes with a gear 69 rigidly attached to the upper end flange 70 of the drum 71. Rigidly mounted in the frame 59 and also bolted to the floor fis a screw 72 which extends co-axially throughand supports the drum 71 for purposes presently fully appearing.

Bolted or otherwise rigidly secured to the rear ends of the uprights 2 in upwardly spaced relation to the footforming frames 8, 8' are brackets 73, 74, 75, 76 which rotatably support spaced parallel horizontalPulleys 77, 78, 79, 80 and also mounted on the adjacent and lateral outer panels 2 by means of brackets 81, 82 are horizontal pulleys 83, 84. 7 Additionally mounted on the lateral outer upright 2 adjacent the bracket 82 is a bracket 85 for rotatably supporting a vertical pulley 86, and pinned or otherwise rotatably mounted on the upright 2 downwardly of the bracket 85 a vertical pulley 87.

Wrapped a plurality of turns around the drum 71 is a cable 88 which extends laterally outwardly on either side of frame 59 and is trained over the pulleys 79, 8 6, .87. The cable 88 extends outwardly toward the forward-most under-frame carriage 41" for connection with a slack takeup device 89 preferably of a typemore fully described and shown in FIGS. 16 and 17 of my co-pending application Serial No. 669,301, filed July 1, 1957, now US. Patent No. 2,898,639, issued August 11, 1959. The device 89 is, in turn, connected to an upstanding bracket 90 on the carriage 41' by means of nuts 91, 92. The other end of the cable 88 is trained over the pulleys '77, 46, 45, and also over the pulleys 48, 51, 53, 55, 58 in a continuous serpentine pattern and is rigidly secured to the forward-most under-frame carriage 41 by means of a cable clamp 93. Also wrapped a plurality of turns around the drum' 71 is a cable 94 which extends outwardly through the frame 59 on both sides thereof and is trained over the pulleys 76, 78, 83, 84. The cable 94 is wrapped around the drum in a direction opposite to that of the cable 88 and is trained in a continuous serpentine pattern over the pulleys 48', 51', 53, 55, 58' and is then rigidly secured to the outer-most under-carriage 41' by means of a cable clamp 93. The cable 94 also extends forwardly from the pulley 83 for direct connection to a slack take-up device 95 which is, in turn, connected to the under-frame carriage 41 by means of nuts 96, 97.

In connection with the present invention, it should be noted that the cables 88, 94 are anchored at both ends to the forward-most extensible under-frame carriages 41, 41', respectively, so that irrespective of which direction the cable is moving, it will never at any time become loose and the same length of each cable 88, 94 will at all times be wound around the drum 53. This construction permits the seating structure A to be self-locking so that when the motor 61 is actuated and thereafter stopped in a position intermediate the fully opened or fully closed position, the seating structure A will remain immovably in such position. The several tiers T of the seating structure A Will normally open in successive order and the lower-most tier T will move outwardly first to the full extent of its travel with respect to the second tier T directly thereabove. Thus the under-frame carriages 41, 41' will move outwardly to the full limit of their travel and will then begin to pull successive under-carriages outwardly after it. Consequently, if the seating structure A is half open, the lower tiers T will be opened out and the under-frame carriages 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 32', 33', 34, 35, 36', 37', 38', 39', 40, 41' will be in the fully extended position. Moreover, since the seating structure A is self-l0cking, it is possible to maintain the entire seating structure immovable in either fully opened or partially opened position.

In use, a conventional forward and reverse type switch can be located at any convenient point within the gymnasium or auditorium and can be manually actuated to energize the motor 61. If the seating structure A is in the fully closed position, the switch can be closed to actuate the motor in the forward direction so as to cause the drum 71 to rotate clockwise" reference being made to FIG. 9. This causes the cable 88 to pay off to the right side of the drum 71 (viewed from FIG. 9) and at the same time Wind on the drum 71 from the other side. The forward end of the cable 88, which is attached through the slack take-up device 89 to the forward-most under-frame carriage 41', is then moved forwardly While the other end of the cable 88 which is attached to the under-frame carriage 41 will be pulled inwardly toward the wall B thereby pulling open the under-frame carriage 41 and the carriages 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 3f), 29, 23, 27, 26, 25, 24, 23, 18, in successive order. Similarly, the cable 94 will pay off to the left (viewed from FIG. 9) and Wind on from the right, and since the forward end of the cable 94 is attached to the carriage 41 through the slack take-up device 95, the cable 94 will move outwardly with carriage 41. At the same time, the other end of the cable 94 is secured to the carriage 41 by the clamp 93 and, therefore, the cable 94 will pull the carriage 41 forwardly which, in turn, pulls open the carriages 4t), 39, 38, 37', 36', 35, 34', 33, 32', 31', 30, 29', 28, 27', 26', 25', 24',

23', 18', in successive order. It will, therefore, be apparent that the two cables 88, 94 act together and each pulls with equal tension along one set of under-frame carriages to open the seating structure A to the position diagrammatically shown in FIG. 3. When it is desired to withdraw the seating structure A into closed position, the switch control is actuated so as to reverse the direction of the motor 61 which, in turn, reverses the rotation of the drum 71 and causes the cables 88, 94 to pull the under-frame carriages 41, 41 toward the wall B. As this is done, the other ends of the cables 88, 94 will be taken up in the convolusions around the pulleys 48, 51, 53, 55, 58, 48, 51, 53, 55, 58.

During the forward and reverse movement of the motor 61, the drum 71 and gear 69 will move upwardly and downwardly along the screw 72 from the positions shown in full and dotted lines in FIG. 9. At the same time the gear 69 will slide along the pinion 68 but will always remain meshed therewith. Thus, the incoming and outgoing portions of the cables 88, 94 will always lie in the same straight lines.

It should also be noted in connection with the present invention that the under-frame carriages 18, 18' may be each provided with an adjustable limit switch for purposes of shutting off the motor 61 when the seating structure A reaches the fully opened or fully closed position. Since the under-frame carriages 18, 18 are the last under-frame carriages to shift during either opening or closing of the seating structure A, a limit switch on these under-frame carriages will stop the rotation of the motor 61 when the seating structure A is: in either the fully extended or fully closed position. The limit switches and their precise details of construction are well known and are, therefore, not shown or described in detail.

It should be understood that changes and modifications in the form, construction, arrangement, and combination of the several parts of the power-operated telescoping seating structures may be made and substituted for those herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A seating structure comprising a stationary back frame and a plurality of horizontally extensible and retractable frames disposed in side-by-side internested relation and being adapted for relative movement outwardly with respect to the back frame and with respect to each other into an extended position and inwardly with respect to the back frame and to each other into a retracted position, seat means carried by each frame for use when the frames are extended, each of said frames being oepratively provided with two longitudinally spaced pulleys, cable means trained around the pulleys, one of said pulleys in each extensible frame being tilted with respect to the other pulley in said frame so as to transfer the cable means from frame to frame without cable overlap in a continuous serpentine course, and a rotatable drum around which the cable means is trained, and power means contained within the confines of the structure in closed position for rotation of the drum, whereby rotation of the drum will shift said frames outwardly into extended position and inwardly into closed position.

2. A seating structure comprising a stationary back frame and a plurality of horizontally extensible and retractable frames disposed in side-by-side internested relation and being adapted for relative movement outwardly with respect to the back frame and with respect to each other into an extended position .and inwardly with respect to the back frame and to each other into a retracted position, seat means carried by each frame for use when the frames are extended, a plurality of floorcontacting carriages joined to the lower ends of each frame and being operatively connected to the adjacent carriage for relative shifting movement with respect thereto, front andrear pulleys operatively mounted on the carriages, cable means trained around the pulleys in a continuous serpentine course, one of said pulleys on each carriagebeing tilted with respect tothe other so as to transfer thecable means from frame to frame without cable overlap, a drum around which the cable means is trained, said cable means also being attached at both ends to the carriages which are furthest removed from the back frame when the frames are in extended position, and power-operated means mounted within the confines of the structure in the closed position for rotating said drum whereby to shift said frames outwardly into extended position and inwardly into closed position depending upon the direction of rotation of the drum. "3'. Ai seating structure comprising a stationary back frame and a plurality of horizontally extensible and retractable frames adapted for relative movement out-' Wardl'ywith respect to the'back frame and with respect to each other into an extended position and inwardly with respect to the back frame and to each other into a retracted position, said extensible frames each including a plurality of spaced uprights, seat means carried by each set of uprights for use when the frames are extended, a floor-contacting carriage mounted 'upon the lower end of each upright and being operatively connected to'the adjacent carriage for relative shifting movement'with respect thereto, each of the carriages being operatively provided with a front pulley and a rear pulley, said front pulleys all being rotatable about a'horizontal axis and said rear pulleys all'being rotatable about an axis which is inclined to the horizontal cable means trained around the pulleys, one of'said pulleys in each extensible frame being tilted with respect to the other pulley insaid frame so as to transfer the cable meansfrom frame to frame without cable overlapin a continuous serpentine course, a drunr around'which the cable means is trained, said cable means also being attached atboth ends to the carriageswhich are furthest removed from the back frame when the frames are in extended position, andpoweroperated means mounted within the confines of the'structure in the closed position'for rotating said drum whereby to shift'said frames'outwardly into extended position and inwardly into closed position depending upon the direction of rotationof the drum. f p f .:4, Aseating structure comprising a stationary back frame and a plurality of horizontally extensible and retractable frames adapted for relative movement outwardly with-respect to the stationary back frame and with respect to eachother into an extended position, and inwardly with respect to the back'frame and to each other into a retracted position, seat meanscarried by each frame for'use when the frames are extended, a plurality of floor contacting carriages joined to the lower ends of each frame and being operatively connected to the adjacent carriage for relative shifting movement with respectthereto, .a front pulley and a rear pulley mounted on each of the carriages, cable means trained around the pulleys in a continuous serpentine course, said cable being routed so that upon extension the lowermost sea t means is extended'first, followed by the next lowermost seat means, and so forth in successive order, and similarly in retraction the lowermost seat means is retracted first, followed by the next uppermost seat means, and so forth in successive order to enable selection of the amount of seat tiers to be used, a drum around which said cable means is trained, said drum being mounted for rotation about a vertical axis to provide continuous on and off cable feed for the same drum, means to shift the vertical position of said drum so the latterrotates whereby to prevent, cable walking, said cable means furtherrnore being attached at both endsto the carriages which, re f h t rem e fr m he ba f am a n the frames are inextended position, and'power-operated means mounted w-ithin the confines of v the structure in the closed position for rotating said drumiwhereby to shift said frames outwardly into extended positionand inwardly into closed positiondepending upon the direction of rotation of the drum; I

5. A seating structure comprising a stationary back frame and a pluralityof horizontally extensible and re tractable frames adapted for relative movement-out: wardly with respectto the stationary back frame and with respect to each other into an extended position, and inwardly with respect to the back frame and to each other into a retracted position, seat means carriedby each; frame for use when the frames 7 are extended, a plurality of floor-contacting carriages joined to thelower ends of each frame and being operatively connected to the adjacent carriage for relative shifting movementzwith respect thereto,,a front pulley and a rear pulleyoperatively mounted on each of the carriages, cable means trained around the pulleys in a continuous'serpentine course, said cable being routed so that upon extension the lowermost seat means is extended first, followed by the next lowermost seat means, and so forth in successive order, and similarlytin retraction the lowermost seat means is retracted first, followed by the next uppermost seat meansand so forth in successive order to enable selection of' the amount of seat tiers to be used, a drum around, which said cable'means is trained, said drum being mountedfor rotation about a vertical axis .to provide c :ontinuous on-an off cable feed for the same drum, an elongated pinion operatively mounted for rotation about a vertical axis, gear means on the drum slidably' engaging and meshing with theelongated pinion," means for shiftingthe drum vertically as it rotates whereby to prevent cable walking, said cable means furthermore being attached at both ends to the carriages which are furthest removed from the back frame when the frames arein extended position, and power-operated means mounted within the confines of the structure in the closed position for rotating'said drum whereby to shift said frames outwardly into extended position andfinwardly into closed position depending upon the direction of rotation of the drum. Y ,7 y i 6; A seating structure comprising a stationary back frame and a plurality of horizontally extensible and re tractable frames adapted for relative T movement out; wardly with respect to the stationary back'frame and with respectto each other into. an extended position, and inwardly with respect to the back frame and to each other into a retracted position, seat means carried by each frame, for use when theframes are extended, a plurality of floor-contacting carriages joined to the lower ends of each frame and being operatively connected to the'a'djacent carriage for relative shifting movement with respect thereto, a front pulley and a rear pulley operatively mounted on each of the carriages, cable means trained around the pulleys in a continuous serpentine course,' said cable being routed so that upon extension the lowermost seat means is extended first, followed by the next lowermost seat means, and so forth in successive order, and similarly in retraction the lowermost seat means ,is retracted first, followed by the next uppermost seatrnean's, and so'forth in successive order to enable selection of the amount of seat tiers to be used, a drum a round which said cable means is trained, said drum being mounted to rotate about a vertical axis to provide continuous onand off cable feed for the same. drum, an elongated pinion, gear means onv the drum slidably engaging and meshing with the elongated pinion, means for shifting the drum vertically as it rotates whereby to prevent cable walking andsaid drum, pinion, gear,means and shifting mean s be ng journaled entirely within the confines of thestrueture inthe closed position,- said cable means running-on 9 10 and ofif the drum in a straight and level course, said Refe ces Cite in the file of this patent cable means furthermore being attached at both ends to UN D STATES PATENTS the carriages which are furthest removed from the back 524,476 Austin Aug 14 1894 frame when the frames are in extended position, and 5 2,898,639 Murphy Aug. 11, 1959 power-operated means mounted within the confines of FOREIGN PATENTS the structure in the closed position for rotating said drum whereby to shift said frames outwardly into extended po- 154709 Austraha 1952 sition and inwardly into closed position depending upon THER REFERENCES the direction of rotation of the drum Progressive Architecture, page 157, Nov. 1954. 

